Marinucci: Maintain test leads, cables to save time, money

Taking care of test leads and cables saves automotive service businesses time, money and grief. Test leads and cables link critical diagnostic gear, such as scan tools, meters and oscilloscopes, to the vehicle.

Ultimately, this gear is only as good as the cables and test leads connecting it to the vehicle.

Questionable leads and cables may fail during diagnosis, skewing measurements and clouding test results. Sometimes a cable or test lead failure scuttles an entire diagnosis, leaving a technician wondering if the trouble began in the vehicle, the tester itself or in a bad test lead or cable.

Unforeseen cable failure also may force a service salesperson to scramble, justifying a delayed repair job to an anxious car owner.

Fortunately, tending to the health of cables and test leads requires less effort than bosses may realize. What's more, prudent owners and managers make this maintenance routine shop practice rather than a hit-or-miss affair.

Here are basic steps for maintaining common leads and cables used to diagnose most parts of traditional, 12.00-volt electrical systems.

Cleaning cables and leads matters for two reasons.

First, routine cleaning helps techs spot any cracked, flaked or burned areas on the insulation or outer jacket. Damaged insulation may allow a lead or cable to short against the metal of the vehicle, disrupting operation of a meter, tester, scan tool or oscilloscope.

Second, this short circuit could disrupt — possibly cancel out — test equipment readings. I have watched techs go crazy trying to interpret illogical or intermittent readings because they overlooked a test lead shorting against the vehicle.

Note that test leads for common scan tools, meters and oscilloscopes carry very low levels of electrical current. Therefore, a test lead shorting to the vehicle usually does not create a telltale arc or make an arcing sound.

Some test gear makers recommend cleaning equipment and test leads with a clean, soft cloth dampened with soapy water. The soap should be a mild soap; dampened means damp as opposed to wringing wet.

For decades now, I have had success dampening the cloth with multi-purpose cleaners such as Cinch, Fantastik, Simple Green and Spray Nine. These types of products have cleaned testers and leads effectively without damaging them.

Beware of common shop chemicals such as aerosol carburetor or brake cleaner. I have seen these cleaners literally melt or distort a test lead's outer jacket as well as the plastic housing of various testers and meters.

What's more, I have seen carburetor and brake cleaners permanently cloud or disfigure display screens on testers, meters, etc. Some techs have a bad habit of reaching for these chemicals whenever you ask them to clean something.

Forewarned is forearmed.

Manhandling a test lead or cable may fracture the fine wire strands inside. Carelessly wrapping a test lead or cable too tightly is one way to damage these strands. Repeatedly bending or twisting it strenuously at the same location is another way.

Sometimes, hurried techs damage these strands by picking up a tester by its leads or cables.

Frayed wire strands inside a test lead or cable may cause a tester's display to flicker or shut off — possibly cause readings to fluctuate illogically.

Carefully flexing or shaking a suspect cable may create or aggravate these annoying symptoms. If that is the case, the test lead or cable is failing.

Another basic trick is substituting known-good, known-comparable leads or cables from another tester or meter. If this substitution eliminates the erratic symptoms, replace the suspect cables or test leads.

Some test leads are more flexible than others. The greater the flexibility, the more easily a tech can wrap them into a compact bundle that fits inside a storage case at quitting time.

Some managers and techs believe that an equipment case is the logical location for test leads and cables. All in the world is not right if leads and cables are not in the appropriate storage case.

Furthermore, keeping everything in the proper storage case has a security aspect. For example, a shop foreman may lock all the meters, scan tools and other testers inside a tool crib overnight.

Many techs lock their personal test gear inside their toolboxes at the end of the day.

However, some managers and techs do not necessarily bundle and stow away every cable and test lead.

First of all, you cannot wrap some cables and test leads tightly without kinking or misshaping them. This prevents them from naturally relaxing — lying flat, if you will — in the work area.

Anyone who has learned to coil a common air hose recognizes the difference between a kinked or knotted hose and one that will unfurl readily again.

A kinked or knotted test lead can be a nuisance if it catches on something — especially when a tech is working in cramped quarters somewhere inside the vehicle.

Second, some techs have damaged test leads by trying to bundle or wrap them too tightly. Therefore, they prefer to coil test leads into a relatively large, relaxed loop.

Some techs stow these looped test leads flat inside a toolbox drawer or hang them on a tool cart or on the side of the toolbox. In some busy shops, frequently used cables and test leads are organized neatly on pegboard hooks.

For one thing, the pegboard format makes leads and cables readily available to all techs. At a glance, a shop foreman can see when one is missing from the appropriated hook on the pegboard — not to mention keep an eye on the condition of each cable or test lead.

This means that a damaged lead or cable does not create an unpleasant surprise when the shop schedule is tight.

There is more than one way to maintain and organize test leads effectively. Choose the method that best suits your needs.